Waveguides are initially etched into an SOI wafer before being wafer bonded to a compound semiconductor die or wafer. The conventional technique that is used for preventing fluids from flowing down an etched waveguide channel is by temporarily blocking the channel at the edge of the region where the SOI wafer is bonded with the semiconductor die with, for example, photoresist or a mounting wax that is commonly used in the polishing-and-lapping industry. The conventional approach shows only moderate success in blocking fluids and is not suitable for high-volume manufacturing as implementation is too variable. A conventional fabrication processing of hybrid silicon-optical devices is illustrated in “Hybrid silicon evanescent device,” A. W. Fang et al., Materials Today, Volume 10, Number 7-8, July 2007.
It will be appreciated that for simplicity and/or clarity of illustration, elements illustrated in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, if considered appropriate, reference numerals have been repeated among the figures to indicate corresponding and/or analogous elements.